A conventional approach for achieving multiple communications functions is to use different set(s) of signal processors, such as modulators/demodulators, for each communication rate. In this configuration, a single processing chain is required for transmitting and another processing chain is used for receiving. Unfortunately, this conventional concept breaks down when the system operates at various speeds without changing the actual processors. There are currently no practical single system architectures that may operate at varying frequencies, while combining different coding spectrums. New approaches for variable rate communications are desirable.